Scientists have found when parents respond to young children in timely and meaningful ways, the tots learn new words better.

The study was conducted by researchers at the University of Washington, Temple University and the University of Delaware.

Three dozen 2-year-olds were randomly assigned to learn new verbs in one of three ways: training with a live person, training through video chat technology such as Skype that allows audio and video interaction via screen between users at different locations, and watching a prerecorded video of the same person instructing a different child who was off screen and thus out of synch with the child in the study.

Researchers found that children learned new words only when conversing with a person and in the live video chat, both of which involved responsive, back-and-forth social interactions.

They didn't learn the new words through the prerecorded video instruction, which was not responsive to the child.

Children who learned in the two environments that involved real-time social interaction even used the new words to label the actions when different people performed them.

"The study highlights the importance of responsive interactions for language learning," said Kathy Hirsh-Pasek, professor of psychology at Temple University, who coauthored the study.

"Interactions allow adults and toddlers to respond to each other in a back-and-forth fashion - such as live instruction and the video chats. These types of interactions seem to be central for learning words," she said.

"The research has important implications for language learning. Children are less likely to learn from videos than from live, back-and-forth responsive interactions with caring adults. Young children are not good at learning language if they're merely parked in front of screen media," Hirsh-Pasek continued.